Find SQL Instance Names

Hi Guys...
I have one server with three named instances of SQL server 2005 installed on it.
and i dont know any thing else about the server. Now i want to connect all 3 instances on the local SSMS. but i don't know the Instance names.
Can anybody tell me how can get the instance names for cennecting them or how can i find how many instances are installed on the server and what are the names.

My Dear Ajith...Thanx for this new command, but I think we can run command only when we are connected to that perticular intance I mean to say through query windows or sqlcmd. But how can i connect to that instance if i don't know the name.

U can go to Services Option under Administrator Tools Option.
You are having SQL Server Services Installed with instance name. If there is no name mentioned after the $ sign then it would be the default instance.
Else, you can find from Add Remove Programm Options. All the server server are installed with the instance name.

HI Satish,
This is one more option, who are not at all familier with SQL Server and commands.
Please refer Log file in the server. Path would be : Program FilesMicrosoft SQL ServerMSSQL.1MSSQLLOG. file name will be 'ERRORLOG'
This file will give you all the information about the instance. You can open this file in notepad.
Regards
-Johnson

Satish
Don't you have any documentation or reference available within this company about the SQL Servers?
I believe you are a DBA over there and you must have all the information available in hand, as you can see various methods given by our members are useful to find what you need. But I would also suggest to take your time in searching for relevant subject here and take a tour with Books online too.